Continuous inductive train-control system



Feb. 26, 1929. 1,703,821

- W. K. HOWE CONTINUOUS INDUCTIVE TRAIN CONTROL SYSTEM Filed Nov; 27, 1925 Patented Feb. 26, 1929;

wm'rnnor K. grown, on ROCHESTER, NEW YORK, Assnmon r0 GENERAL PQTENT RAILWAY s-rGnAL coMPANY, on ROCHESTER,- ,REW rom.

CONTINUOUS Innocrrvn Application. filed November This invention relates to automatic train control and more particularly concerns a train Control system of the continuousinductive type. Y 7 Y IligeIlCIfll, train control systems are d'e-' signed to add a certain element of safety to train operation over and above that which is aliordedby the usual operation of the train by the engineer in accordance with the indi cations of Wayside signals. To accomplish this purpose, it has been considered advisable to design train control systems in such a'manner that the engineer will be encouraged to nia'ataina constant vigilance in his observation of the wayside signals, and to operate the train in accordance with their indications.

One system which carries out this idea of encouraging the observance oi-signal indications by the engineer employs -so-called acknowledging means, that is, a suitable manually operable means is provided which must be properlyoperated by the engineer at points along the trackway where traffic conditions, as indicated by the wayside signals or by the cab signals, change froinclearto caution or from type of s) t in, favorable trafi'ic conditions aheadare usualiy indicated by the flow of alternating current n the track rails or other wayside conductors,=a change to unfavorable conditions lifilig indicated by the fact that this current ceases to flow. ,As a train proceeds over trackway territory in which unfavorable traiiic conditions exist, the trackway current remains off, and the engineer is not reminded by any further operation'oii the carcarried apparatus that he isproceeding in dangerousterritory. It is evident that-suitable means i or requiringrthe performance of a manual acknowledging act at predetermined intervals whentlietrain is passing: successive stop or danger signalsis very desirable, as it is mos important: tomaintain the engineers vigilance while he is'operating in trackway the trans TRAIN-CONTROL sY s'rlm.

27 i925. Serial No. 71,371.

tions exist ahead.

With the above and otherconsiderations in mind it is proposed in accordance with the present invention to provide an automatic territory where continued dangerous condi- .train control system of the continuous indtic tive type in which nieans'are provided for en forc ng the acknowledgment of all unfavorable indications of the wayside signals, and

more specifically it is proposed toprovide a 6 system .ofthis type in which a restrictive pen} alty is imposed the engineer does"'not perform a suitable nrariual act when the firstand all subsequent successive unfavorable signals are encountered." Qth'er objects, advantages and characteristicfeatures'of the invention will become apparent as the description thereof progresses.

In describing the invention in detail, reference will be inadeto' the accompanying drawing in which the ti'ackvvay and are r-- ried apparatus of iii-simplified continuous d'uctive train control system 'Ofthe two-position type, embodyingth'e' present invention,

has been shown in'a diagrammatic" manner.

Referring to-the drawing, the trackway apwith continuous inductive trainf control, and as this equipment is well known to those skilled in theart, it will be rather briefly described. V V V Thetra ck rails 1 are divided iiitoblocks by the insulating-joints 2, the'blockrl andthe ends of the two adjacent blocks H and havingbeen shown. I In'oi'd'er to simplify t-l'iedisclosure. the corresponding elements and devices in the various blocks have been indicated by like reference characters having distinctive exponents. The normal direction 'oftraflic over the trackway is indicated by the arrow.

The usual track relays 3 are connected across the track. rails at the entrance em; of each block, being normally energized by the track battery t connectedacross the track rails at the exit end of each block as shown. Alternating train control. current is supplied to the two track rails in series through the transformer 5, the. secondary winding of which is connected across the track rails in series with. the battery 4' asclearlyl shown.

transformer 6 through a circuit including the paratus is of the usual typen'sed in connectionv i contact finger 7 and front contactvof 7 track rel:

tiirmer 6-being energized from a 3 o'f'the first block in advance,"

105 The transformer 5 is energized from a second transmission line or other suitable source of alternating current.

Wayside signals of the semaphore, color. light, or other suitable type are preferably used in connection with the present invention,

and the semaphore signals Z have been conventionally illustrated in the drawings at the entrance, end of'each block, the well known operating devices and circuits for these signalsbeing omitted to simplify the disclosure. In carryin out the present invention, it

is necessary to transmit an impulse-to the vehicle for a short distance of travel in each block'under unfavorable trafiic conditions and this is conveniently accomplished by pro Viding so-called tracklocps near the exit end of each block. Each tracl; loop 8 con- 7 sists of a wirearrangedto extend parallel the track'loop 8 of that block.

to the track rails for a short distance near the exit end of each block, alternating train control current being supplied to this wire from thetransformer 6 through a circuit including the contact finger C 1 and back contact 9 of the track relay 3 of the first block in ad Vance. The track loop 8 -is so mounted as to produce an i alternating magnetic field near the track rail 1 which induces voltages in the recelvlng apparatus on thevehicle 1n the same manner as would the fieldfroin an alternat ing current in'the track rails. The track loops 1n the various blocks'are of equal length for reasons hereinafter described.

' From the description of the trackway apparatus given above, will be evident that;

occupied or danger block behind the train located therein,or in the track rails of a'caution block, that is, the first block to the rear of an occupied block and the trackloop in the caution block is energized with train control current. I r q A railway vehicle has been conventlonally represented in the block H by the wheels and axles 10. This vehicle is provided with the usual-receivingcoils 11 which are mounted ahead of the leading axle of the vehicle and in'induc-tive relation to the track rails 1. The coils 11, which mayor may not be pro vided with laminated iron cores, are so connected that voltages induced therein as'a rersultof alternating currents flowing in oppo site directions in the two track rails are additive. series with the input circuit of a suitableain- The receiving coils 11 are connected in plifying device Awhich may take any one of a number of preferred forms, such as an speed responsive device is provided.

audion tube amplifier of the well known type. "his receiving input circuit may be tuned to resonance at the. frequency of the train control current by .nieansof a condenser of suitable capacity ifdesired. The output circuit of the amplifier A- is connected to a suitable quick acting main car relay MR, which maybe of the alternating current or of the direct current type. f r i As certain of the vehicle controls are dependent upon the vel'iicle speed, a suitable This speed responsive device may take any suitable form, and hasibeen shown as a simple centrifuge G, of the fly ball typ6-CO111p1'1S ing the'usual fixed collar 12 andslidable col lar 13 mounted on a shaft 1 and normally biased apart'by a spring 15. Thelinks 16 and 17 carrying the weights 18 are pivotally connected to the collars 12 and 13, the movable collar 13 having a groove therein which is operatively engaged by a lever 19 connected to a speed 20. The arrangement is such'that the upward moven'ient of the slidable collar 13 as the speed-of theshaft 1% increases, turns the speed shaft 20 through the lever 19 in a clockwise direction. The shaft 1 1 is suitably connected through gearing, belting or other suitable means to an axle of the vehicle, 7

The speed shaft 20 *arries'a can1'21 which isenga'ged by a suitable movably mounted contact finger 22, biased to the position shown, the arrangementbeing such that the V finger 22 is moved by the cam 21 to eng' e a stationary contact 23 when the speed shaft 20 is in a position corresponding to a very lowvehicle speed such as one or two miles per hour; arranged to close the contacts 22 and 23 only when the vehicle is at a stop. The driving shaft 1% carries a worm gear 2% 1' idly se cured thereto, and this worm gear is engage l bya pinion 25, suitably secured to a shaft The shaft 26 carries a second pinion 2? w" is in continuous driving:engagement x, .1 two gears 28 and 29. I

The gear 28 is rotatably mounted on a shaft 30 which also carries a, bracket 31 having three 11111332, 33 and 345 extending radially from the shatt 30. The arm 33 carriesa gear 35 which is in driving engagement with gear 28. The arm 32 carries two gears 36 and 37 If desired, the cam 21 may he iii) which are in driving engagement with each other and are driven by the gear 28, the gears 36 and 37 being locatedin a different plane from that of the gear 35. A cam shaft is mounted adjacent to the gear 285 and carries two mutilated gears 39 and a0, fixed t-o'the end thereof; the gear 39 being in the plane of the ear 35 and the ear 40 b61119" 1n the )lane Vb F- n m 1 of the gears 3. and 30.- ihe-arin 34 or tne o I Jo L 11 bracket 31 extends horizontally irom U116 shaft 30 and is biased upwardly by a spring 11, this arm 3e together with the arms 33 and mcaaa to disengage the gear .39 and the gear '37,

to engage the gear-40, thus turning the shaft 38 in the ,opposite direction .until' it has reached its original position as shown with the gear 37 opposite the mutilated portion of the 40. It should be observed that the return or reverse speed of the shaft 38when driven through the gears 36 and 37 is higher than the run-down speed when this shaft is driven through the gears and 39 for the reason that the gears 37 and 40 are more nearly equal in diameter than are the gears 35and39.'

The shaft 38 carries three cams, 43, 44 and 45, which are arranged to control the en gagementof the movablecontact fingers 46, 47 and 48 with their stationary contacts '49,

50 and 51, respectively, as hereinafter de i the spring 73 to normally remain n its raised position as shown. The shaft 72. carr eS an scribed. V I g The gear 29 drives a second cam shaft 52 through a reduction gear train comprising the pinion 53 fixed on'the shaft 54 with the gear 29 and the gear 55-with the pinion 56 both fixed to the shaft 57 The shaft 57 is carried by a bracket 58 which is pivotally secured to the shaft 54 and is extended beyond the shaft 57 to form a horizontally ex- 3 with the gear 61. The shaft 52 is thereby rotated at a'low speed as compared with the speed of rotation of the shaft 38, theextent of this rotationbeing limited by the mutilated portion of the gear 61. Vhen the magnet 60 is again energized, the-shaft 52 is returned to its normalposition as shown by means of a spring 62. i

The vehicle speed may be controlled in any suitable manner, and in the system shown, means are provided for controlling the, ve-

hicle speed in accordance with distance of travel from the point at which influences corresponding to unfavorable traffic conditions ahead. are first received. 7 This speed distance feature is provided for by means of a per n'iissive speed cam 63 secured to the shaft 52 and engaging one end of a floating lever 64, the other end of whichis moved by an arm 65 fixedly secured. tothe' speed shaft 20. The

movement of an intermediate point; on the lever 64 is proportional to a function of the vehicle speed and its distance of travel from the point at which the ma net- 60is de-energized and the shaft 52 initiated. The tmg lever 64 operates a contact sector Q66 through a link 67, the sector 66 being biased in a counter-clockwise direction by the spring 68. The sector .66 operates a movable contact finger 69through the roller 70, the firiger 69 being normally biased to disengage its stationary contact 71, and being held in engagement therewith by the sector As the vehicle speed increases, the sector 66 is'turned in a clockwise direction, the contacts 69 and '71 being permitted to open when a given speed is reached, "this speed being dependent upon the distance of vehicletravel from they point at which unfavorable trafiic conditions are first encountered. l I The vehicle-carried apparatus includes a manually operable acknowled ing contact'or, designated as a whole as N. may take any suitable form which is convenient for manual operation, and as shown com.- prises a vertically disposed shaft 52 slidably mounted in suitable supports an; biased by his cont-actor insulated movable. contact mflrnb erfz which i engages the stationary contacts '75 and 76 when the contact-or is in its normalposition as shown, and connects the stationary contacts 77 and 78 when the cont actor is depressedi' An armature 79 is secured to the lower em of the shaft 7 2, and a magnet 80 is arranged directly below this armature in such a position that the energization of the magnet 89 will retain the contactor N in its operative position against the bias of thef spring 73 with the contacts 77 and 78 bridged by the contact 74. The contactor N is preferably mountedatsome point in the locomotive cab at which it may be easily reached the engineer.

In order that the engineer may be informed'as to the point in the vehicle travel at which the acknowledging co itactor N must be operated, a suitable cab signal S is provided. This signal mav'beof tlieandihle or visible type and as shown com rises a simple incandescent light of the wel 'known 1 type. A protection'relay PR- is provided in conjunction with the acknowledgin eontactor N, this relay ein ofthe well nogiv'n direct current type and ein g provided. with suitablequick acting contacts.

The vehicle' brakes may be controlled. in any suitable manner and by means ofanyone of: a number .of well known devices a-(la ted for this purpose. As the initiation 0 an automatic brake application is "usuall a? complished by means of the deenergizatiop of some suitable electro magnetip'devipe, he

device K has been shown, it being assume that the deenergization of a c rcuit through its -windingswill act insome suitable man'- tlo nor to initiate an automatic application of the vehicle brakes. A stick relay R of the V usualtype is provided for use in connection which may be traced asffollou with the device K as hereinafter described. Operatiom rlts shown in the drawings, all ot the track-Way and ear-carrieddevices and circuits-are in their normal operating positions, that 1s, 1n the positions assumed With a train travelling at speed in a clear block and with all circuits and de ices pro; v

other tra'in in either of the blocks 1 and J.

Under these conditions, tram control current flows in the track rails of the block H ahead of tllGVGlHClG under consideration, and serves to induce voltages in the receiving coils 11. These volt-a es are nnoressed on" the merit O r i 5 c rcuit of the amplrher A and cause the energization of the main relay MR. ll ith theanain relay MR energized, the cam starter magnet: a2 is energized throu 'lracircuit battery terminal B, cont ct linger 90 and frontcontact 91 0t the'relay MR, Wire 92,

' and the Winding of the magnet- 42 to the batteryterminal C. With the cam starter magnet 42 energized, the cam shaft 38 is retained in the position shown, the contacts a6 and l9 beingclosed by the cam as, and the contacts 48 and 51 being closed by the cam 45; With the contacts 46 and 4f) closed, the cam-starter magnet is energized through the following circuit :.from the battery terminal 13, contacts 4:6 and 49, Wire 96, back contact and contact finger 97 01 the relay PR, wire 98,

and thewinding of the magnet 60 to the battery terminal C. The cnergization "oil the main relay MR also causes the energisation of the stick relay B, through a circuit which may be traced as follows :fro m the battery terminal B, contact linger 8i andfront contact of the main relay MR, Wires 82 and-83,

' front contact and contact finger S t of the stick relay R, Wires 85 and 86and the Winding ofthe relay R to the battery-terminal C. The

7' stick-relay R is also energized througha circuit including the contacts L8 and 51 of i the cam 45, and the Wire 941:, Whichcircuit is. p V

say 100 lit. the cam l3 permits the movable hereinafter traced. Niththe stick relay R energized; the brake applying device K is energized'through a circuit which maybe traced as follows:'from the battery nal B, contact finger'tlil and stationary contact 7 1,\Vl18 87 contact finger 88 and front Contact of the stick relay R, Wire 89 and the Windingo'f'the device K to the battery terminal C. lVit-h the device 1C energized the vehicle brakes may be released by the engitrainis located. in the block a.

nected to the speed shaft 20 acts to move the sector 66 into position to open the contacts 69' and 71 when the speed (retriever ":le becomes excesslve. il henthe cents 71 are disengaged the energizing circuit "for the device K, traced above, is broken at this point, and an automatic application'o'rthe brakes results. This automatic brake application persists until the trainspeed re duced below the high speed limit, at which time the COILZICJCS 69 andTl are again closed by the sector 66, thus re-energizing the device K, and permitting the release of the brakes by the engineer. l j 7 Considering now the oper on of the tr under consideration under caution. :11. I conditions, assume that the train under con sideration enters the block I Wl'Pll another T Under t conditions, no train control current flows in the track rails of the block I and hence be main relay MR is ale-energized as soon as the train enters this block. The de-enereizat n1 ot' the main relay MR causes the immediate de-energization of the cam starter magnet 42, the energizing circuit for this magz net hen g broken by the disengagement of the contact finger 90 of the'relay his andvits front contact 91. It should be observed that the stick relay it is not ale-energized by the retraction of the contact linger 81 or" the main relay MR, as an alternate energizing circuit for this re lay it exi which circuit may be traced as follows lio a the battery terminal'ld; movable contact linger lS and stationary co 51 of the cam a5, wires 93, 9 S3 and 95, front contact and contact linger-8d the relay R, wires 85 and 86 and the winding ot the relay it to the battery terminal C. The deenerg'sation of the cam starter magnet 4:? permits the spring 41 to move the arm 34 upv'ardly,'thus gaging the gea11s'35 and 39. The shaft is then turned in accordance with the'inotion oi the vehicle, and after a re-determined distance of vehicle travel.

contact finger lGto disengage its stationary contact 49.. This openingof the contacts 46 and 49 breaks the energizing circuit for th cam starter magnet 60, which circuit has been traced above and the spring 59 moves the pinion 56 into engagement with the TD" lated gear 61,:thus-turning theshaft 0Q accordance 'Withthe progress of the vehic After the vehicle has proceeded a slig the cam 44 moves the contact finger 47 into.

engagement with the stationary contactbt) thereof, thus completing an energizing circuit tor the acknowledging; signal which cir cult maybe traced as tollo :-trom the battery terminal B, movable Contact ll and stationary contact 50, wires 99 and 100, stationary contact 75, movable contact 75 and stationary contact 76 ot' the acknowledging contactor N, wire 101 and the signal S to the battery terminal C. v e r ,7 V i It the engineer is on the alert and has properly observed-and recognized the caution in di-eation ot'the wayside signal Z located at the entrance end of the block I, heis aware of the fact that he is operating underunfavorable traffic conditions ahead, and is there fore on the lookout for the operation of the acknowledging signal. The operation of the acknow dging signal S at this point informs the ori ear that he has reached thepoint in the cautionblock at which he must operatethe acknowledging contactor N. and, assuming in this casethat the engineer does so operate the acknowledging contactor, a circuit is established for energizing the relay PR, which circuit may be traced as tollowsz from the battery terminal B, stationary contact 77.

movable contact 74 and stationary con of the contactor N, wire 102 and t of the relay PR to the battery terminal C. The energization of the relay PR causes its contact finger 103 to engage its front contact and the finger 97 to disengage its back contact. Just after the contacts 47 and 50 are closed by the cam 44, the cam is turned to a position to permit the contact finger 48 to disengage its stationary contact 51, thus breaking the energizing circuit for the stick relay R, ich circuit has been traced above. It, hon ,cr, the engineer has operated the acknowledging contactor l and energized the relay PR as described above, an alternate energizing circuit for the stick relay R is established before the energizing circuit through the contacts 48 and 51 is broken. This alternate energizing circuit may be traced IiOll'OWS1-fl0l11 the battery terminal B, front contactand contact linger 103 e 1e rel a PB, wires 104C, 9- 83 an d 95, front contact and contact finger 84; ot the relay R, wires and 86 and the winding of the relay R the noted that ran engineer need not maintain the acknowledging contactor N in the depressed pof 'on for the distance of travel during v. i the contacts 48 and 51 of the cam 45 remain open, the acknowledging contaetor being maintained in its closed position by means of the magnet 80 which is energized as tery terminal C. It should be contact 47 and stationaryconta ct of the cam 44, wires 99 and l OS and the magn'et to the battery terminal C. Asthetrain under consideration proceeds beyond the acknow -ledging point, the cam {15, again closes the con tacts 48' and 51, thus, com leting energizedcircuit for the stick relay which has been traced above,and the cam 44 opens the energizinv circuit for the magnet 80, thusreleasthe acknowledging contactor N. The

relay PR is de energized when the contactor,

N is released, the energizing, circuit for the relay PR beingcompleted as described above. At this point inthe vehicle travel the cam shaft 38 has been turned through an angle of rotation of 180 degrees, andthe gear 35' is opposite the mutilated ortion ofv the gear 39. At this point the shaft 38 is no longer turned and the circuits established are maintained as the vehicle proceeds through the caution block.

The speed of the vehicle as it proceeds through the caution block is'limited b the permissive speed mechanism described a ove. The cam shaft 52 is slowly turnedthrough thereduction gears, moving the permissive speed cam 63 to impose more, restrictive speed limits, and if the train speed is not maintained belowlthese limits the sector 66 is turned to such a position-that the contacts 69 and 71 are opened, deenergizing the brake applying device K and causing an automatic brake application which persists until the vehicle speedhas been reduced. to a value below the permissive limit. The train may thus proceed through the cautionblock under the restriction of the automatic control provided the engineerhas-properly acknowledged-the caution signal just after entering this block.

, As the train under consideration approaches the exit end of the caution block, the receiving coils 11 encounter the magnetic field surrounding the energized track loop 8,

and the main relay MR is again energn'zed.

gear 35 out of engagement with the gear 39 and causes the gear 37 to engage the gear 40, thus turning the cam shaft 38 in the reverse direction at a rapid rate. The length of track loop 8, is so arr: nged that the cam shaft '38'is returned about half way or 90 degrees while the vehicle traverses this track loop and this loop is the same length in each block, in

order to obtain uniform operation at each loop. That is to say, the camshaft 38 is returned to a pointatwhich the cams 43, 44 and 1f) maintain the contacts lo-and 49 open, the contacts {t7 and open, andthe' contacts 428 and 51 closed. As the train under consideration leaves the track loop 8 and enters the occupied block J, the main relay MB is again (lo-energized and the cam starter magnet-l2 is therefore de energized, permitting the gear to engage the gear 39 and again drive the shaft 38 in the run down direction. After a very short distance of vehicle travel, the contact finger 4:7 is again moved into engagement with its stationary contact 50 by the cam 44, thus energizing the acknowledging signal S and the magnet 80. At this point the engineer, having properly observed and recognized the danger indication of the signal Z at the entranceto the block J, again operates the acknowledging contactor N, energizes the relay PR and establishes an alter V nate energizing circuit for the stlck relay R while the contacts 48 and 51 of the cam are opened; It should be noted that the cam shaft 52 was turned thevehicle proceeded through the caution block to impose more and more restrictive speed limits as this cantion block was traversed, the drivmg mechanism for this cam shaft being arranged so block.

cations of the wayside signals 2111i. operation of the acknowledging cab signal S that the mutilated portion of the gear 61 comes opposite to the-pnnon-SG when the train is nearing the exit end of the caution As'the cam shaft 38 is not returned far enough, when the track loop is encoun tered, to close the contacts 46 and 49 of the cam 43, the cam starter magnet GOremains de-energized and the cam shaft 52 remains in its run down position, and continues to limit the train speed to the low permissive value as thetrain proceeds in the occupied block J.

The train under consideration now proceeds through the block J atthe low permissivespeed, and 1f the train 111 advancc'pro cceds into the nextadvance block, thus imposing caution traiiic conditions in the block J, the train under consideration encounters the energized track loop at the exit end of the block J and theengincer is forced to operate the acknowledging contactor N in the mannor described above in connection with the block I. trackway t rritory in which unfavorable tran ic conditionsrahead exist the engineer is required to perform a manual act by operating the acknowledging contactor N in each block in which dangerous traffic conditions exist.

If the engineer is not attentive 'i.

and runs into a block in which caution traiiic conditions exist withoutoperating the contactor 1 ,'the stick relay R is tie-energized when the cam l5 reaches the point at which the contacts 48 and fil'are opened. The deenergization of the stick relay R causes the d'e-energization of the brake applying device K by opening the energizing circuit for this device through the contact linger 81 and front contact of the relay R. The de-energi- Thus as the train proceeds over zation of the device K causes an automatic brake application Which persists until the train speed has been reduced tov a very low value, say one or two miles per hour, at

which speed the cam 21 moves the contact,

linger 22 into engagement with the stationary contactLS, and a pick up circuit for the stick relay F.- is established. This pickup circuit may be traced as follows :from the battery terminal B, contacts 48 and 51 of the cam 45. wire 9% 83 and 10'? contact lin 'er 22 and stationary contact 23 of the cam 21, wires 108 and 86, and the winding of the relay to the battery terminal C. Once energized, the stickrelay R moves its contact linger 842 into engagement with its front contact and a stick circuit is established through 48 and 51 for energizing this relay, which stick circuit has been traced above. The reenergization of stick re ay Rcloses the energized circuit for the device K through the contact finger 88 and front contact of this relay; this energizing circuit hasbeen traced above. With the device K energized the train under consideration may again proceed through the caution block under the control of the permissive speed mechanism.

If in like manner the engineer fails o v properly acknowle lge the unfavorable indi-' cation of successive cautionor danger signals at the points indicatedby the operation of the acknowledging cab signal S, the train speed is automatically reduced to. a very low value, practically to a stop, thus penalizing the engineer with the annoyance and delay occasioned by such automatic stop.

' Means are provided for preventing the en gincer from using the acknowledging contactor N to prevent an automatic brake application or speed restriction-while travelling under unfavorable traffic conditions. Should the engineer secure or otherwise maintain imposed as described above. .lhis restricmitsthe re-cnergization of the cam'st-arier magnet 60.

It maybe observed that when the cam shaft 38 is returned in the reverse direction in passing an energized track loop 8 uni er unfavorable trailic conditions, the contacts and 51 are momentarily opened by the cam so and the contacts Hand are momentarily closed by the cam 4A.- This operation of the 'pohitssuch as sivitchfrogs, cross overs, and

the like are encountered at which these train control currents must be cut off for a short distance of vehicle travel. The present system so designed that the momentary lack of train control currents in the track rails at these dead sections, as they are some- 7 times called, will not impose a speed restriction or pe'nalty. As a train equipped with the system shown encounters one of these dead sections alongthe traclnvay, the main relay MB is (le -energized and the cam starter magnet 42 is also de enei'gized as described above, the stick relay B- Vbeing maintained energized through the contacts 48 and 51 of the cam -15. The cam starter magnet 60 is I not deenergized until the vehicle has {noceed'ed a predetermined distance, say ft. at which point the cam 43 permits the d1sengagement of the contact fingers and 49.

This distance preceding the de-energ'izati'on of the magnet is so arranged as to be in excess of the longest dead section distance ordinarily encountered in. practice. After the dead section istraversed and the train control currents again effect the energization of the main relay MR, the cam starter magnet 42 is i e-energized and the cam shaft 38 is returned to its original normal position" by the gears '37 and 40, no automatic restric tion having been imposed as a result of the momentary lack of control current in the track rails.

From the description given'it 'will be observed that an extremely simple and eflicient System of train control has been devised in whichacknowledgment of all unfavorable signal indications by the engineer is enforced,

and in which the failure of the 'engineerto properly acknowledge initial or successive unfavorable signal indications results in the imposition of a pen alty, it isevident'tha't by the use of this type of control system the en gineer is encouraged to inaintain a careful observation of the wayside signal indications, and is particularly encouraged to be vigilant in his .obser ation of these indications while proceedin, under unfavorable trafiic conditions aheadp I v Althoughthe present invention has been described in connection with a rather specific system of train control embodying certain specific devices and circuits, it should be clearly understood thatthe invention is not liin'i'ted to the particular construction and arrangement shotvn, and that certain changes, modilion-tions, and combinations might be inirde without depaiting from the scope of the invention as defined by the appended claims.

What it is desired .to secure by Letters Patent is '1. 'In an automatic train control system of the continuous inductive two-position type, means for continuously transmitting influences from the 'tracl tivay to a moving vehicle under favorable 'trailic conditions and for cuttrolled by said control device acting to who,

inati'caily reduce the vehicle speed when said influences are not transmitted, apparatus associated with said control device for causing an automatic brake application and bringing the vehicle substantially to a stop when thetrain travels in adverse traffic territ'ory Without interfering with the proper.

functioning of 'said speed restricting means, andnianually operable means acting if opertried at predetermined successive points along the trackvva'y under unfavorable tra'ffic conditions to prevent the operation of ratns; I '2. In an automatic train control system, trackvvay means for continuously transmit ting influences to a moving vehicle under favorable traliic conditions and for cutting off said influences under unfavorable traffic conditions ahead, car-carried apparatus 'cbmprising a control device responsive to: said influences, automatic speed restiicti'n apparatus controlled byisa'id control device and acting to impose increasingly restrictive speed limits asthe vehicle proceeds under unfavorable traific conditions and elfecting a brake application if such speed limits are exceeded, and further automatic brake control apparatus for initiating an automatic brake application to bring the vehicle substantially to a stop if a manually operable device is not operated Within predetermined distance intervals While the train is proceeding under trackway means for continuously transmit ting influences to a moving vehicle under favorable trafiic conditions and for cutting oil said influences under unfavorable trafic said appaconditions'ahead, car-carried apparatus coInprising a control means responsive to said influences, a distance operated device controlled by said control means and initiated when said influences are cut off, said distance operated device acting to initiate a spe d con trol' means and to set up a restrictive control after a predetermined distance of vehicle operable means acting it operated to prevent V sald automatic brake application. 71o

4. In an automatic train control system of the continuous inductive type in which a control current flows in the traclrrails undo favorable traffic conditions and is cut olt under unfavorable trafiic conditions ahead, car-carried means responsive to said control wcurrent for controlling. the vehicle speed in accordance with the flow of said current, means for automatically applying the vehicle brakes and bringing the vehicle substantially V to a stop upon the entrance of the vehicle into a traclrway section where said control current is cut off, manually operable means acting to prevent said automatic brake application it operated at a predetermined distance from the point at which said control current is cut d, and further tracltway means at spaced points for initiating said automatic brake applying means when the vehicle is traveling under unfavorable traflic conditions unless said manually operable means is operated at a predetermined dlstance from said spaced points.

5. In an automatic train; control system of the type in which influences are continuouslv transmitted from the traclrway to a movii vehicle under favorable tra'ffic conditions fonly, car-carried apparatus comprising a device driven in accordance with the motion of the vehicle and initiated when said influences are cut off means tor settin uo a n Iv 0 o I I V a resoective speed limit initiated by sai d (.GVJCQ at a predetermined distance of vehicle travel from the point at which said influences are cut oil', means controlled by said device tor initiating an automatic brake application at a predetermined distance of vehicletravol from the point at which said restrictive speed .nieans' isfinitiated said brake application brin 'in the vehlclesubstantiallv to a stop, E3 9 .1 1,

spaced trackivay means for operating said device to initiate an automa atpredetermined succes \c points under uu favorable trailic conditions, and manually operable'means acting to prevent said autovmatic brake applications it operated at said point where said influences are first cut oil and at said predetermined successive points. 6. In an automatic train control system of c the type in which control. currents flow in the track rails under favorable traliic conditlons andare cnt oltunder unfavorable traltic co'n- V ditions ahead, car-carried apparatus compris- I ing a relay energized in response to the flow of said control currents, a control device adapted to be driven n accordance with the ic brake application motion of the vehicle and initiated by the de-energization of said relay, saidcontrol. device acting successively to initiate a restrictive control and to impose an automatic brake application after the vehicle has traveled a predetermined distance from the point at which said control currents are cut oil and said relay is die-energized,current-carrying means at spaced points along the tracltway for energizing said relay to reset id control device and thereby to impose said automatic brake application at said spaced points under untavoral le tral'lic conditons, manually operable means for preventing said automatic brake application, and means for releasing said automatic brake applications, if not prevented'by said manually operable means, only after the vehicle has been brought subs t-anti ally to a stop. 1

7. In an automatic train'control system of the type in which control currents flow in the track rails under favorable traffic conditions and are cut ofli under unfavorable tr'atlicconditions ahead, car-carried apparatus comprising a relayenergized in response to the "flow of said control currents, a control device adapted to be driven in a cordance with the motion ofthe vehicle from an initial pother traclrway means spaced points for carrying control currents andmomentarily energizing said relay at said points under unfavorable tratiic conditions, whereby said device is reset at said points and an automatic brake application is initiated unless said manually operable device is operator predetermined distance from each of said points.

8. In an automatic-train control the type in which control currents flow in the track rails under favorable tratlic conditions and are cut on under unihivmfable trallic conditions ahead, car-carried.apparatus CGll'lPI'lS ing a relay energized in response to thetlow oi. said control currents, a control device adapted to be driven in accordance with the motion of the vehicle from an initial position to a run-down positionjwhen said relay is do energized and to be reset to said initial position when sai'dr'elay'is re-energized, means for restricting the vehicle speed, initiated by said control device after said device has run down a predetermined amount, further means controlled by said device for initiating an automatic brake application after said device an L1,

tern of p ihas nun down a further predetermined 1. amount; means for I releasing said automatic brake application only after the vehicle has 4 been brought to a "stop, I manually I operable 5 means fon reventin said automatic brake- 23 application it operated before said device has run down- :said 1 predetermined amount -and f'urther trackway mea ns at spaced points for -=carrying control'currents and moi'nentarily -energi'zing said-relay at said poi-nts'under unfavorable traflie conditions, whereby said device is'reset atsaid points and an automatic "adapted to be driven'i-n accordance-witlrthe motionoft-hevehicle from an initial position toa' run-down position when said main-relay 1s de-energized and to be reset to saidinitial position when-said mainrelay- 1s -re-energ1zed,

acting to apply the vehicle brakes when deenergized, an energizing circuit for said brake applying device including a front contact of a stick relay and contacts of a permissive speed device, said permissive speed device acting to open said contacts if the vehicle speed. exceeds a predetermined value after said device is initiated, a stick circuit for said stick relay closed by said cont-r01 device when in its initial posit-ion and opened after said control device has run down a predetermined an'iount, an alternative stick circuit for said stick relay, manually operable means for closing said alternative stick circuit, means operated by said control device for initiating said permissive speed device after said control device has run down a predetermined amount, a pick-up circuit for said stick relay closed only when the vehicle is substantially at a stop, and t-rackway means at spaced points for momentarily energizing said main relay under unfavorable traflic conditions to reset said control device a predetermined amount whereby said manually operable means mustbe operated at said spaced points under unfavorable traflic conditions to prevent the de-energization of said stick relay and said brake applying device, and a consequent automatic brake application.

10. In an automatic train control system of the continuous inductive type, the combination with a relay energized under clear traffic conditions in response to current flowing in the track rails, of a distance device operable in accordance with the progress of the vehicle and controlled to be operated in accordance with such progress in one directrafiic cond =t ingin the track rails, of a distancede'vice said distance device;

11. In an automatic train control-system of the continuous inductivetype,the combination with a relay-energized under clear ions in response to current flowoperable in accordance withthe progress- :of

the vehicle and controlled to be operated'in accordance Wlth such progress'inone direction when said relay is energized and in t'he 0t-l1eI d1Ie0t1OI1'Wh8n said relay is jde-energized, the rates of such operationbeing dif -so -ferent in the two directions, and brakecom --trol means governed by said distance'idevice.

ECCOI'dRYIOG with such progressin enedirec--- tion when said relay isenergizedand--in the other direction when said relay-isdevenera-normally-energized brake applying device gizedytherate of operation insaidone'direction being greater than in said other direction and brake control means governed by said distance device.

13. In sin-automatic train control'system of the continuous inductive type, the combination with a relay energized under clear trafiic conditionsin response to currentflowing in the track rails, of a distance device operable in accordance with the progress of the vehicle and controlled to be operated in accordance with such progress in one direction when said relay is energized and in the 106 other direction when said relay is de-energized, means for effecting an application of the brakes of the vehicle upon a predetermined extent of operation of said distance device, and manually operable means for pre- 110 venting such application of the brakes.

14. Car-carried apparatus for automatic train control systems comprising, a distance device operated in accordance with the progress of the car, brake applying means controlled by the distance device, and means associated with the distancedevice forrautomatically preventing operation of the brake applying means until a predetermined distance of car travel after initiation of the 1 distance device, means controlled by trackway conditions for driving the distance device in opposite directions at different speeds, the higher speed corresponding to energized trackway conditions and the lower'to deenergized trackway conditions.

15. In a train control system, a car-carried relay energized under favorable t-raflic conditions ahead and de-energizedunder unfavorable trafiic conditions ahead, a control device arranged to be driven at a given rate in accordance with the progress of the car from an initial to a run down position when said relay is de-energized and be driven back to said mitial position in accordance with the progress of the car if said relay be subsequently re-energized for a suificient length of time, car speed restricting means initiated by saidcontrol device after a predetermined amount of movement toward run down position, brake settmg means 1n1t1ated after said control device has moved a predetermined amount toward run down position, acknowledging means for preventing initiation of i so doing by operation ofsaid acknowledging means.

16. In a train control system, a car-carried relay energized under tavorable traffic conch- ,tions ahead and de-energized under unfavorable trafiic conditions ahead, a control device arranged to be driven at a given rate in accordance with the progress of the car from an-initial to a run down position when said relay is de-energized and be driven back to said initial position at a faster rate than said given rate in accordance with the progress oi the car if said relay be subsequently re-energized for a sutficient length of time, car speed restricting means initiated by said control device after a predetermined amount of movement toward run down position, brake setting means initiated after said control device has moved a predete mined amount toward run down position, acknowledging means for preventing initiation of said brake setting means, but not affecting said speed restricting means, it operated in time, and trackway means to only momentarily reenergize said relay under unfavorable traffic conditions to cause said control device to be driven but part wayback to said initial position whereby to initiate said brake setting means at a point a given distance beyond said trackway means unless prevented from so doing by operation of said acknowledging means. r

In testimony whereof I affix my signature.

l/VINTHROP K. HUWE 

